Egg peritonitis or egg yolk peritonitis (coelomitis) describes inflammation of the serosal surfaces within the coelom of a hen in response to yolk material that has been deposited into the body cavity (see ). The inflammatory response may be sterile initially, but yolk material is an excellent bacterial growth medium, prone to infection by bacterial organisms, most commonly Escherichia coli.
Cases complicated with bacterial infection are characterized by fibrin or caseous albumen-like material with a cooked appearance among the abdominal viscera. Egg yolk peritonitis, complicated with bacterial infection, is a common cause of sporadic death in layers or breeder hens; however, in some flocks, this may become the major cause of death before or after reaching peak production and give the appearance of an infectious disease. It is diagnosed at necropsy.
Peritonitis, which may or may not be initiated by yolk deposition in the abdomen (coelom), follows reverse movement of albumen and E coli bacteria from the oviduct into the abdomen. If the incidence in a flock is high, culture should be done to differentiate between Pasteurella multocida (fowl cholera Fowl Cholera ) and Salmonella infection Salmonelloses .
Antimicrobial treatment of peritonitis caused by E coli infections is usually ineffective, likely due in part to the extent of disease in the coelom. Management of body weight and uniformity, reproductive development (ovary follicle growth and maturation), and drinking water sanitation are the best preventive strategies.
Overfeeding broiler breeder hens during sexual maturation can increase the number of large yellow ovarian follicles (see ). When hens have too many large ovarian follicles, a problem described as erratic oviposition and defective egg syndrome (EODES) results. This condition is accompanied by a high incidence of double-yolked eggs, prolapses of the oviduct, internal ovulation, or internal laying that often results in egg peritonitis and death.
EODES is prevented by avoiding light stimulation of underweight pullets too early and by following guidelines for body weight and uniformity and lighting recommendations for each breeder strain. Overweight hens may also have a higher incidence of erratic ovulation and mortality associated with egg peritonitis.